This invention relates to a full type tapered roller bearing having means for preventing separation of the rollers.
Ordinary tapered roller bearings comprise an outer ring having a radially inner, tapered raceway, a flanged inner ring having a radially outer, tapered raceway extending between the flanges at both ends of the inner ring, and tapered rollers disposed between the raceways of the inner and outer rings. The rollers are retained by a retainer. The retainer serves to keep the rollers circumferentially aligned and spaced apart from each other at equal intervals. The retainer also prevents the rollers from falling off during transportation or assembly, or when one of the inner and outer rings is removed.
Full type or retainer-less tapered roller bearings are also known (see JP patent publication 07-293558). By omitting the retainer, it is possible to increase the number of rollers used and thus to increase the rigidity of the bearing. Because this type of bearing has no retainer, the rollers tend to fall off during transportation or assembly. Thus, this type of bearing has various means for preventing a fall of the rollers, such as a snap ring fitted on the raceway of the outer ring, and a ring member mounted on the large-diameter end face of the outer ring (see FIGS. 1 and 6 of the above publication).
Such a snap ring limits, i.e. shortens the effective width of the raceway of the outer ring, thereby shortening the rollers, which in turn lowers the load-bearing capacity of the bearing. Further, since the snap ring is mounted on the outer ring, if it is necessary to remove the outer ring, the snap ring has to be removed, too. Thus, if the outer ring is removed, there is no means for preventing separation of the rollers. The ring member does not lower the load-bearing capacity of the bearing. But because it is mounted on the outer ring, if the outer ring is removed, nothing can prevent separation of the rollers.
Thus, while the abovementioned snap ring and ring member can effectively prevent separation of rollers e.g. during transportation, such means cannot prevent separation of rollers while the outer ring is not mounted, such as when inspecting the bearing by removing the outer ring.
An object of the present invention is to provide a full type tapered roller bearing which can prevent separation of the rollers, not only during transportation but while the outer ring is not mounted, without lowering the load-bearing capacity of the bearing.